code: def action(self) -> Optional[str]:
      # action: "{" ~ target_atoms "}"
      mark = self._mark()
      cut = False
      if (
          (literal := self.expect("{"))
          and (cut := True)
          and (target_atoms := self.target_atoms())
          and (literal_1 := self.expect("}"))
      ):
          return target_atoms
      self._reset(mark)
      if cut:
          return None
      return None
  
imports: import ast
  import sys
  import tokenize
  from typing import Any, Optional
  from pegen.parser import memoize, memoize_left_rec, logger, Parser
  from ast import literal_eval
  from pegen.grammar import Alt, Cut, Forced, Gather, Group, Item, Lookahead, LookaheadOrCut, MetaTuple, MetaList, NameLeaf, NamedItem, NamedItemList, NegativeLookahead, Opt, Plain, PositiveLookahead, Repeat0, Repeat1, Rhs, Rule, RuleList, RuleName, Grammar, StringLeaf
label_desc: Use image node_id 18 for calling the GeneratedParser obj's underlying member method code with example usage: obj.action() and returns: None, target_atoms, None